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Sensitivity in polymer-bonded explosives (PBXs) relies on the presence of defects, such as cracks and voids, which create localized thermal energy, commonly known as hotspots, and initiate reactions through various localization phenomena. Our prior research has explored the use of internal gas pressure induced by thermite ignition to generate localized defects for PBX sensitization. However, further research is required to gain a more comprehensive understanding of the defect generation process resulting from internal gas pressure. This study investigates the process of defect generation in PBXs in response to internally induced gas pressure by applying controlled compressed gas to a fabricated cavity within the materials, simulating the gas pressure emitting from thermite. X-ray micro-computed tomography was employed to visualize the microstructure of the sample before and after gas injection. The experiments reveal the significance of gas pressure, cavity shape, temperature, and specimen compaction pressure in the defect generation. Numerical simulations using Abaqus/Standard were conducted to assess the defect generation in mock PBXs under varying gas pressures, cohesive properties, and binder thicknesses. The simulation results demonstrate the substantial influence of these properties on the ability to generate defects in mock PBXs. This study contributes to a better understanding of the factors influencing defect generation in mock PBXs. This knowledge is crucial for achieving precise control over defect generation, leading to improved ignition and detonation characteristics in PBXs. [ABSTRACT FROM AUTHOR]

To solve the severe coal dust pollution and dust hazards in underground coal mines, this study utilized graft copolymerization modification technology and compound technology to develop a mining composite consolidation dust suppressant. On this basis, analysis of its consolidation wettability and dust suppression mechanism was conducted through characterization tests and molecular dynamics simulation methods. The results show that polyacrylamide (PAM) had been successfully grafted onto the soybean protein isolate (SPI) molecule, and form a SPI‐PAM complex. After the dust suppressant acted on the coal dust surface, it utilized its wealthy hydrophilic groups, for the adsorption of water molecules and the positive amide group for binding to produce a large area of agglomeration of coal dust particles at the interface, exhibiting good wetting and consolidation into a shell. At the same time, molecular dynamic simulation verified that the diffusivity of water molecules in the dust suppressant‐coal system was 0.30Å2/ps, decreased by 43.3%, and the interaction energy with coal molecules was −200.27 kcal/mol, absolute value increased by 41.35%, which made the dust suppressant molecules more easily adsorb and agglomerate on the surface, demonstrated an excellent solidification and dust suppression effect. [ABSTRACT FROM AUTHOR]

During processing in deep convective cloud systems, highly viscous or glassy secondary organic aerosol (SOA) particles can develop a porous structure through a process known as atmospheric freeze‐drying. This structural modification may enhance their heterogeneous ice nucleation ability under cirrus conditions through the pore condensation and freezing mechanism. Pristine, compact SOA particles, on the other hand, are recommended to be treated as ice‐inactive in models. This recommendation also applies to internally mixed particles, where a coating layer of secondary organic matter (SOM) deactivates the intrinsic ice nucleation ability of the core, which may be a mineral dust grain. Ice cloud‐processing may also improve the ice nucleation ability of such a composite particle by inducing structural changes in the coating layer, which can release active sites on the mineral surface. In this work, we investigated the change in the ice nucleation ability of pure SOA particles from the ozonolysis of α‐pinene and two types of internally mixed particles (zeolite and coal fly ash particles coated with SOM) after being subjected to the atmospheric freeze‐drying process simulated in an expansion cloud chamber. For pure α‐pinene SOA, we found only a slight improvement in the ice nucleation ability of the ice cloud‐processed, porous particles compared to their pristine, compact counterparts at 221 and 217 K. In contrast, the zeolite and coal fly ash particles, which were initially deactivated by the organic coating, became significantly more ice‐active after atmospheric freeze‐drying, emphasizing that such composite particles cannot be excluded from model simulations of heterogeneous ice formation. Plain Language Summary: Understanding how ice crystals form in the Earth's atmosphere is important for predicting climate using cloud models. It is believed that certain surface features on atmospheric aerosol particles, such as cracks and pores found on mineral dust grains, can effectively induce ice formation. Ice crystals are formed from small amounts of liquid water that have condensed and frozen in the pores of the particles. As a result, ice formation is less likely to occur on solid particles that lack such pores and have a smooth surface. One type of the latter are particles formed by the condensation of volatile, biogenic and anthropogenic organic compounds. In models of ice formation, such secondary organic aerosol particles are often neglected because of their compact, non‐porous shape. In our work, we simulated a pathway by which such particles can acquire a porous structure through cloud‐processing in the atmosphere, and investigated how this affects their ability to form ice. We also investigated mixed particle types in which the organic compounds condensed on a mineral surface, blocking the pores that allowed efficient ice formation. The aforementioned cloud‐processing partially restructured the organic material on the mineral surface, and the particles became more effective at forming ice again. Key Points: Regardless of particle morphology, pure secondary organic aerosol particles are inefficient at nucleating ice under cirrus conditionsA pristine coating layer of secondary organic matter deactivates efficient ice nucleating particles such as mineral dust and coal fly ashIce cloud‐processing changes the structure of the coating layer and partially restores the ice nucleation ability of such mixed particles [ABSTRACT FROM AUTHOR]

This article explores the collection and study of Australian mining songs, specifically those related to gold and coal mining. The author notes a lack of documentation on industrial folk songs and conducted field collecting trips to coal mining towns to gather songs and stories. The article discusses the role of songs during strikes and demonstrations, as well as the changing opportunities for collecting songs through online resources. It also examines the themes and perspectives found in mining songs, including excitement, practicality, despondency, and grievances. The article highlights the increase in literacy among coal mining workers and the circulation of songs through printed materials. It questions whether modern-day miners create songs and mentions the presence of anti-mining songs. Resources for further exploration of Australian mining folklore are provided. [Extracted from the article]

Coal seam water injection is an effective technique for dust reduction in coal mines. Imbibition is an important means of water transport in coal seams and is influenced by coal bedding. The spatial distribution of water in the seepage process was obtained, and the spontaneous seepage characteristics and water transport mechanisms of coals containing different layered angles were revealed by NMR. Results show that the bedding mainly serves as the water flow channels in the imbibition. When the angle increases, the imbibition rate of adsorption pores and seepage pores in the early stage decreases. The imbibition is firstly transported to the top quickly along the bedding flow channel, 1.5h for 0° bedding coal sample, 24h for 90°, when the water reached its apex, the curve no longer changed and imbibition proceeded slowly. With the increase of bedding angle, the imbibition equilibrium time increased from 3h to 30h, up to 9 times more, the maximum imbibition rate decreases significantly, reduced from 5.64 g/h to 1.13 g/h, the flow resistance increases, and the remaining capillary force after equilibrium increases from 0.007 Pa to 5.24 Pa. When the capillary force cannot overcome the flow resistance, the imbibition reaches equilibrium. [ABSTRACT FROM AUTHOR]

• The hybrid cooling and dust suppression solution that prioritizes efficiency, energy saving, and environmental protection has been proposed. • The effects of the hybrid cooling and dust suppression solution in hot fully-mechanized mining face have been conducted by computational fluid dynamics numerical simulation. • The hybrid solution will be of benefit to the improvement of the thermal and clean environment. With the increasing depth of coal mining, the hot and humid environment at the mining faces is becoming more severe. Mining in these conditions, coupled with the hazardous effects of coal dust, poses a significant risk to the health of coal miners. To improve the working conditions in underground coal mines, this study proposes a hybrid solution that combines evaporative cooling and dust suppression in fully mechanized working faces. Numerical models of the mining face are also created to simulate the cooling effects of the proposed solution. Additionally, the migration laws of water droplets from the spray system are also studied. The results indicate that the proposed solution can effectively improve thermal environments and suppress coal dust. This research can enhance the workplace safety in underground coal mines and provide valuable insights for addressing high airflow temperatures and concentrated dust levels. [ABSTRACT FROM AUTHOR]

Estimating foliar dust (FD) is essential in understanding the complex interaction between FD, vegetation, and the environment. The elevated FD has a significant impacts on vegetation physiological processes. The present study aims to explore the potential of multi‐sensor optical satellite data sets (e.g., Landsat‐8, 9; Sentinel‐2B, and PlanetScope) in conjunction with in situ data sets for FD estimation over the Jharsuguda coal mining region in Eastern India. The efficacy of different spectral bands and various radiometric indices (RIs) was tested using linear regression models for FD estimation. Furthermore, the study attempts to quantify the impacts of FD on vegetation's physiological processes (e.g., carbon uptake, transpiration, water use efficiency, leaf temperature) through proxy data sets. The key findings of the study uncovered sensor‐specific and common trends in vegetation spectral profiles under varying FD concentrations. A saturation threshold was observed around 50 g/m2 of FD concentration, beyond which additional FD concentration exhibited limited impact on spectral reflectance. On the other hand, the assessment of FD estimation models revealed distinct performances and shared trends across various satellite sensors. Notably, near‐infrared and shortwave infrared‐1 bands, along with certain RIs, such as the Global Environmental Monitoring Index and the Non‐Linear Index, emerged as pivotal for accurate FD estimation. Besides, the study results revealed that vegetation‐associated carbon uptake experienced a ∼2 to 3 gC reduction for every additional gram of FD per square meter. Moreover, the vegetation transpiration reduction per unit of FD ranged from approximately 0.0005 to 0.0006 mm/m2/day, highlighting a moderate impact on transpiration levels. These findings aid a significant evidence base to our understanding of FD's impact on vegetation physiological processes. Plain Language Summary: Estimating foliar dust (FD) cover is essential to understand its impact on vegetation and the environment. Elevated FD levels can reduce photosynthesis, hinder carbon sequestration, and affect transpiration, thereby altering plant health and ecosystem functions. Accurate FD estimation helps in assessing these ecological impacts and developing strategies to mitigate adverse effects. Furthermore, FD can affect remote sensing‐based analysis by altering the spectral reflectance properties of vegetation, potentially leading to inaccuracies in vegetation‐related studies (e.g., health assessment, productivity estimation, species identification, etc.). By understanding these effects, the study shall aid in refining remote sensing models for more precise vegetation analysis. So, the present study utilizes multi‐sensor optical satellite data sets (Landsat‐8, Landsat‐9, Sentinel‐2B, and PlanetScope) along with in situ data to estimate FD in the Jharsuguda coal mining region in Eastern India. Vegetation's spectral profiles under dusty and non‐dusty conditions are also studied. This study also quantifies the impacts of FD on vegetation physiological processes, providing critical insights into the ecological consequences of dust accumulation on plant surfaces. Key Points: Demonstrated an approach to predict foliar dust concentration from satellite dataEvaluated the efficacy of spectral bands of 4 satellite sensors and 26 radiometric indicesQuantified the effect of foliar dust on vegetation physiological processes [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) show great application potential with their unique and excellent performances. Coal and its derivatives are rich in aromatic ring structure, which is suitable for preparing CDs in microstructure. Coal‐burning dust from coal‐fired power plants can be utilized as a rich resource to separate and extract CDs. It is shown in the results that there are two main possible mechanisms for the formation of CDs in coal‐burning dust. One is the self‐assembly of polycyclic aromatic hydrocarbons contained in coal or produced by incomplete combustion of coal. The other mechanism is that the bridge bonds linking different aromatic structures in coal break, which will form CDs with different functional groups when the coals burn at high temperature. Under violet light excitation at 310–340 nm or red light at 610–640 nm, CDs extracted from coal‐burning dust can emit purple fluorescence around 410 nm. The mechanism of up‐conversion fluorescence emission of CDs is due to a two‐photon absorption process. The recycling of CDs from coal‐burning dust from coal‐fired power plants are not only good to protect environment but will also be helpful for mass production of CDs. [ABSTRACT FROM AUTHOR]

Introduction: Information on bioavailable Iron (BAI) content in respirable coal dust (RCD) is crucial to address occupational health and safety, especially in preventing coal workers' pneumoconiosis (CWP). Materials and methods: In the present study, we determined BAI concentrations in seventy-seven coal samples collected from ten coal mining regions of Central India. The cytotoxic potential of BAI-RCD was established invitro by using alveolar epithelial (A549) and macrophage (U937) cell lines. The oxidative/antioxidant status, inflammations, and genotoxicity attributed to BAI-RCD exposure were evaluated and correlated with CWP pathophysiology. Results: The mean BAI concentrations in the coal samples (n = 77) range from (275 to 9065 mg kg-1) and showed wide variability. Both cell lines were exposed to low (275 mg kg-1), moderate (4650 mg kg-1), and high (9065 mg kg-1) BAI-RCD samples showed significant (p < 0.001) cytotoxicity in a dose-dependent manner (low < moderate < high) compared to the control. After BAI-RCD treatment, both cell lines showed a decrease in antioxidant stress measures (SOD, CAT, and GSH) and a significant (p < 0.001) increase in oxidative stress parameters (NADPH, MPO, LPO, and PC). Furthermore, these cell line models demonstrated a statistically significant (p < 0.001) dose-dependent increase in cytokines (TGF-β1, IL-1β, TNF-α, MCP-1, and IL-6 cytokines) and oxidative DNA damage marker (8-OH-dG). Conclusion: Results indicated that the central India coals (even at low BAI content) may be accountable for inflammatory responses and cytotoxicity. Hence, BAI can be important characteristic to establish safety standards for coal dust exposure before active mining. [ABSTRACT FROM AUTHOR]

This paper studied the minimum ignition temperature of the dust layer (MITL) of oil-immersed coal and the heat effect and apparent activation energy (Ea) of raw coal and oil-immersed coal. Based upon the results, the addition of crude oil to coal could reduce the MITL, ameliorate the ignition sensitivity, and increase the heat effect of coal dust. The average Ea of oil-immersed coal was lower than that of raw coal. When there was a 10.8 mass% oil-immersed concentration of oil-immersed coal with the most acceptable particle size (≤ 75 μm), the MITL was 24.24% lower than that of raw coal. Furthermore, the exothermic value of oil-immersed coal was 26.67% higher than that of raw coal. Besides, the average Ea of oil-immersed coal was 26.8% lower than that of raw coal. The research herein is expected to improve people's understanding of the thermal hazard characteristics of oil-immersed coal dust, reduce the risk of coal dust fires and explosions, and ensure production safety. [ABSTRACT FROM AUTHOR]

Shuozhou is a typical coal mining city, and the Pingshuo Antaibao open-pit coal mine in its area is one of the largest open-pit coal mines in China. The mining of coal resources is an important part of ensuring national energy security, and at the same time, it inevitably has a certain impact on the ecology, such as coal dust generated by open-pit mining will affect air quality, soil, water and vegetation. It is of great significance to explore the temporal and spatial variation of ecological environment quality in coal mining cities for ecological protection and sustainable social and economic development. Based on the Google Earth Engine (GEE) platform, this paper combines the index-based coal dust index (ICDI) and Remote Sensing Ecological Index (RSEI) models to construct an improved RSEI (IRSEI) that can reflect coal mining cities. This paper explores the spatial–temporal evolution characteristics and spatial correlation of ecological environment quality in Shuozhou from 2000 to 2020. The results showed that the average value of IRSEI in Shuozhou was between 0.262 and 0.418, and the overall change showed an upward trend. The growth areas of ecological environment quality are mainly located in the eastern and southwestern areas with good vegetation growth, and these regions have vigorously implemented the Northern Shelter Forest Project, afforestation and greening projects, implemented the forest resource management and protection responsibility system, promoted the construction of ecological civilization, and significantly improved the ecological environment. While the declining areas are mainly located in the central and southern regions where mining activities and human activities are more intensive. The IRSEI in the study area showed a significant spatial positive correlation, and the agglomeration types of the spatial pattern were mainly high-high and low-low agglomeration types, with the high-high agglomeration types mainly distributed in the eastern and southwestern regions, and the low-low agglomeration types distributed in the northern and south-central regions of the study area. The trend of low and low agglomeration has decreased, which further proves that the ecological restoration measures taken by the government, such as returning farmland to forests, integrating protection and restoration of mountains, waters, forests, fields, lakes, grasslands, and sands, controlling soil erosion, and stage wise reclamation of coal mining subsidence areas, have improved the ecological environment quality of Shuozhou. This study provides a reference for understanding the spatiotemporal changes of the ecological environment of coal mining cities, and is conducive to formulating appropriate ecological protection strategies. [ABSTRACT FROM AUTHOR]

The extraction of coal from open-pit mines significantly contributes to environmental degradation, posing grave risks to human health and the operational stability of machinery. In this milieu, microbial dust suppressants leveraging microbially induced carbonate precipitation (MICP) demonstrate substantial potential for application. This manuscript undertakes an exploration of the dust mitigation efficiency, consolidation attributes, and the fundamental mechanisms of microbial dust suppressants across coal dust samples with varying metamorphic gradations. Empirical observations indicate that, in resistance tests against wind and rain, lignite coal underwent mass losses of 7.43 g·m−2·min−1 and 98.62 g·m−2·min−1, respectively. The production of consolidating agents within the lignite dust, attributable to the microbial suppressants, was measured at 0.15 g per unit mass, a value of 1.25 and 1.07 times greater than that observed in bituminous coal and anthracite, respectively. Scanning electron microscopy coupled with X-ray energy-dispersive spectroscopy (SEM–EDS) and X-ray diffraction (XRD) analyses illuminated that the consolidating products within the coal dust predominantly constituted calcite and vaterite forms of calcium carbonate. The consolidation mechanism of coal dust via microbial suppressants is articulated as follows: Subsequent to the application on coal dust, the suppressants induce the formation of carbonate precipitates with inherent adhesive properties. These carbonates affix to the surfaces of coal dust particles, progressively encapsulating them. Furthermore, they play a pivotal role in bridging and filling the interstices between adjacent dust particles, thereby culminating in the genesis of a dense, cohesive mass capable of withstanding erosive forces. [ABSTRACT FROM AUTHOR]

The quest for scientifically advanced and sustainable solutions is driven by growing environmental and economic issues associated with coal mining, processing, and utilization. Consequently, within the coal industry, there is a growing recognition of the potential of microbial applications in fostering innovative technologies. Microbial-based coal solubilization, coal beneficiation, and coal dust suppression are green alternatives to traditional thermochemical and leaching technologies and better meet the need for ecologically sound and economically viable choices. Surfactant-mediated approaches have emerged as powerful tools for modeling, simulation, and optimization of coal-microbial systems and continue to gain prominence in clean coal fuel production, particularly in microbiological co-processing, conversion, and beneficiation. Surfactants (surface-active agents) are amphiphilic compounds that can reduce surface tension and enhance the solubility of hydrophobic molecules. A wide range of surfactant properties can be achieved by either directly influencing microbial growth factors, stimulants, and substrates or indirectly serving as frothers, collectors, and modifiers in the processing and utilization of coal. This review highlights the significant biotechnological potential of surfactants by providing a thorough overview of their involvement in coal biodegradation, bioprocessing, and biobeneficiation, acknowledging their importance as crucial steps in coal consumption. [ABSTRACT FROM AUTHOR]

Background: By 2030, chronic obstructive pulmonary disease (COPD) will become the third leading cause of death globally according to the World Health Organization (WHO) prediction. COPD exacerbation, its flared symptoms causing economic and health burdens to the patients, especially those in lower-to-middle income countries, however, its aggravating factors are yet poorly clarified and under-acknowledged. Objective: The present study aimed to detect patients at high risk of frequent exacerbations based on their individual risk factors, which may minimize cost and damage of the disease. Materials and Methods: The study population was the 268 COPD-diagnosed patients coded with "J440" or "J441" of ICD10, with spirometry results, followed-up at the COPD clinic of Sanam Chai Khet Hospital in 2023, and visiting the clinic in January, 2023. The dependent variable was the number of acute exacerbations resulting in hospitalization in 2023, independence variables were gender, age, underlying diseases, baseline FEV1, BMI, smoking status, and forms of 1-year dust exposures. The associations among these variables were measured by multiple risk regression analysis. Results: The incidences of infrequent and frequent exacerbations were 74.63% and 25.37%, respectively. After adjusting for the confounding factors, the factors, such as 30% to 49% of FEV1 (GOLD 3) (IRR 2.36, 95% CI 1.32 to 4.20), overweight and obesity (IRR 0.45, 95% CI 0.20 to 0.97), smoking status including both former (IRR 4.66, 95% CI: 1.45 to 14.94) and current smokers (including those who were less than 1-month ex-smoker) (IRR 6.88, 95% CI: 2.09 to 22.65), chronic exposure to organic (IRR 2.47, 95% CI 1.28 to 4.78), and coal dust (IRR 2.80, 95% CI 1.46 to 5.36) had shown significant associations with frequent exacerbations. Conclusion: COPD exacerbation, a crisis in healthcare systems, flared up by multi-factors. Smoking, its most common cause, was strongly supported by the present study with significant associations in both current and ex-smokers. Baseline lung function and BMI are suggested to be considered for further investigations. Chronic exposure to dusts such as coal and organic dust, are preventable but under-acknowledged factor, especially in lower-to-middle income countries where agriculture and factory works are the main income of their rural populations. [ABSTRACT FROM AUTHOR]

Pneumoconiosis is the most common occupational disease among coal miners, which is a lung disease caused by long-term inhalation of coal dust and retention in the lungs. The early stage of this disease is highly insidious, and pulmonary fibrosis may occur in the middle and late stages, leading to an increase in patient pain index and mortality rate. Currently, there is a lack of effective treatment methods. The pathogenesis of pneumoconiosis is complex and has many influencing factors. Although the characteristics of coal dust have been considered the main cause of different mechanisms of pneumoconiosis, the effects of coal dust composition, particle size and shape, and coal dust concentration on the pathogenesis of pneumoconiosis have not been systematically elucidated. Meanwhile, considering the irreversibility of pneumoconiosis progression, early prediction for pneumoconiosis patients is particularly important. However, there is no early prediction standard for pneumoconiosis among coal miners. This review summarizes the relevant research on the pathogenesis and prediction of pneumoconiosis in coal miners in recent years. Firstly, the pathogenesis of coal worker pneumoconiosis and silicosis was discussed, and the impact of coal dust characteristics on pneumoconiosis was analyzed. Then, the early diagnostic methods for pneumoconiosis have been systematically introduced, with a focus on image collaborative computer-aided diagnosis analysis and biomarker detection. Finally, the challenge of early screening technology for miners with pneumoconiosis was proposed. [ABSTRACT FROM AUTHOR]

The wettability of coal is of great significance to coal seam water injection and dust prevention. In order to study the influence mechanism of surfactant on the wettability of coal dust surface, the coal dust deposition experiment was carried out with the anthracite in Guizhou mining areas as the research object, and the surfactant solution with the best wetting effect was selected. With the help of infrared spectroscopy experiment and Zeta potential measurement experiment, the change law of coal surface wettability under the action of surfactants was explored. The results show that: the four surfactants used in the experiment can greatly improve the wettability of coal dust. Among them, 1% APG has the best wetting effect on coal dust; after modification, the hydrophilic groups and hydrophobic groups of the experimental coal samples increased, but the increase of hydrophilic groups was significantly greater than that of hydrophobic groups. It shows that the effect of surfactant modification on hydrophilic groups is more significant, which is beneficial to improve the hydrophilicity of coal dust surface; after modification, the surface negative charge of the experimental coal sample increased by about 7.68 times, causing the shear surface in the electric double layer to slide to the liquid surface, and strengthening the dipole force between the oxygen-containing functional groups and the water molecules, resulting in the thickening of the hydration layer and the improvement of the surface wettability of the coal sample.

Droplet distribution characteristic is one of the key factors to determine the dust reduction effect of the spray system. In order to study the droplets distribution characteristics under different conditions, the effect mechanism of airflow speed and spray angle on the droplets distribution characteristics was analyzed based on CFD simulation; in addition, the characteristics of droplet distribution after the spray nozzles are arranged near the shearer are also investigated. The results indicate that different airflow speed and spray angle conditions caused an increase in the longitudinal height and transverse length of the spray belt mainly by increasing the transverse momentum of the droplets. With the increase of wind speed, the momentum shielding effect between droplets at different spatial locations becomes more prominent, which further increases the difference of transverse momentum between droplets and enhances the convergence effect between droplets, resulting in the formation of large-particle droplets around the spray zone. The increase of the spray angle mainly changes the distribution ratio of the outlet momentum in the transverse and longitudinal directions, and the momentum of all droplets in the space is more uniform, which has no obvious effect on the spray particle size distribution characteristics.

ABSTRACT Respirable crystalline silica (RCS) poses significant health risks in workplaces, including underground coal mines, metal and nonmetal mining, construction sites, fire suppression, and oil and gas industries. Raman spectroscopy offers a promising avenue for direct analysis of RCS on sample filters with minimal pretreatment. However, the presence of organic compounds (OC) in the samples can generate fluorescence signals that interfere with RCS measurements, potentially saturating the detector even at short integration times, particularly when using portable Raman instruments. This study explores a novel approach to address these challenges by functionalizing filters with a hydroxyapatite/silver bromide/titanium dioxide (HAT) photocatalyst, facilitating the oxidation and removal of OC using the Raman excitation laser. Photocatalytic degradation experiments conducted on polyvinyl chloride (PVC) filters preloaded with HAT and anatase titanium dioxide (TiO2) particles demonstrated that HAT significantly enhances the degradation of OC, such as oxalic acid, under visible light irradiation compared to TiO2. Additionally, fluorescence interferences were reduced for coal dust samples analyzed on functionalized silver filters using a portable Raman instrument. The efficacy of HAT in OC photocatalytic degradation on silver filters was further confirmed using a benchtop micro‐Raman system. Filter functionalization had minimal impact on filtration efficiencies and pressure drops, indicating the feasibility of this approach for improving RCS analysis while maintaining filter performance. [ABSTRACT FROM AUTHOR]

The removal and discharge of coal powders from coalbed methane wellbore is the key to maintaining continuous production. For this reason, based on the submerged jet theory, the force and migration starting conditions of coal powder particles deposited at the bottom of the coalbed methane well are analyzed by analyzing the cohesiveness of coal powders, and a model for the starting and migration of coal powders at the bottom of the well under submerged jet conditions is established; Considering the adhesion between coal dust, the adhesion coefficient is used to characterize the adhesion between particles, a mechanical model of coal dust particles deposited at the bottom of the well is established, and the corresponding calculation formula for the outlet flow rate of the coal dust cleaning nozzle is derived. The fluid mechanics parameters of the bottom of the well coal dust cleaning under different conditions are obtained, and the numerical simulation method is used to simulate the whole process of jet flushing of the bottom of the well coal dust deposited, and the effect of the bottom of the well jet flushing of coal dust deposits is analyzed, providing a theoretical basis for the bottom of the well coal dust flushing process. [ABSTRACT FROM AUTHOR]

Purpose: Studies have recently shown a correlation between the elemental components of coal dusts, including potassium aluminosilicates, and the lung response as a potential driver for lung diseases associated with inhalation of coal dust. Here we aimed to systematically review the evidence for the association between exposure to potassium bearing dusts and lung outcomes in human studies as well as adverse cellular response in animal/cell culture studies. Methods: A systematic search of the National Library of Medicine (PubMed), Embase and Web of Science was conducted in May 2024. Studies regarding exposure to potassium bearing dusts and aluminosilicates and respiratory consequence were included in the search. Articles were screened, with a secondary assessment for relevance and extraction of key information using a systematic review process. Results: We identified 64 studies, of which 35 were human studies, 22 involved animal experiments and 12 were in vitro studies with 5 papers having both in vivo and in vitro studies. Our review found some evidence that a range of potassium rich dusts increased incidence of respiratory symptoms and lung diseases, although the effect on radiological changes in the lung and pulmonary function loss was not consistent. The in vivo animal and in vitro studies consistently demonstrated an inflammatory response and cytotoxic effect after exposure to these dusts. Conclusion: Given complexity in the dust compositions and lack of direct evidence attributing these specific responses to potassium, we are not able to conclude the effect of potassium minerals in coal on development of respiratory diseases, warranting further research. [ABSTRACT FROM AUTHOR]

Autoignition and smoldering of coal dust have gained great safety concern in both industry and mining due to their high susceptibility to heating. To better understand their controlling mechanism, autoignition and smoldering of bituminous coal particles (1-mm diameter) and coal powders (0.1-mm diameter) in the form of bulk layer heated by 4–45 kW m−2 thermal radiation levels were systematically studied. The results showed that the critical heat flux was between 4 and 5 kW m−2 for both samples. Under 5 kW m−2, no morphology change was detected on surface, but internal ignition and smoldering occurred. Partial oxidation and intense glowing ignition were observed under heat fluxes of 10 and 15–45 kW m−2, respectively. The average glowing temperature was 782.4 ± 19.6 K, while the maximum temperature during smoldering changed in 976–1206 K. Smoldering spread rate of powder sample was larger than that of particle sample due to emerged cracks during heating and larger specific surface area, and both spread rates linearly depended on heat flux. The linear dependency of ignition time to the power of − 0.5 on heat flux in classical ignition theory was found still valid for glowing ignition of both samples, and apparent thermal inertia and critical heat fluxes were quantitatively estimated. In all smoldering tests, mass loss rates exhibited a bimodal feature, with first peak charactering moisture evaporation, while the second peak indicating coal-oxygen reaction. Under 35 and 45 kW m−2 heat fluxes, a unique faint blue flame appeared which depended more on surface temperature than on mass flux of pyrolyzates. This contribution may deliver useful reference for evaluation of coal fire risk and help mitigate hazard of smoldering in practical applications. [ABSTRACT FROM AUTHOR]

Ventilation is critical in underground coal mining (UCM) for safety and productivity. Challenges include mitigating hazardous gases, preventing coal dust accumulation, and achieving a balance between extraction efficiency and environmental concerns. Optimization techniques address these challenges, aiming for enhanced safety, productivity, and sustainability. But, these algorithms need careful tuning and adaptation to dynamic mine conditions to prevent suboptimal solutions and ensure robust optimization performance. Hence, in this research work, a hybrid optimization-based control system is proposed for energy consumption minimization of mine ventilation fan and load management in UCM. The proposed hybrid optimization process is formulated into multi-objective optimization solutions like energy-saving optimization and load management in coal mines. The proposed hybrid optimization technique is the combination of both the Border Collie optimization (BCO) and Aquila optimizer (AO), and hence, it is named as BCOAO technique. At first, based on the ventilation on demand (VOD), the energy consumption is minimized using BCO technique and obtains the optimal main fan speed profile. With this procedure, the energy saving is improved as a consequence, healthy atmosphere with higher performance in the mines. Secondly, based on the time of use (TOU) tariff, the mining schedule starting time is found and analyzed in the load management using AO technique. The performance is carried out in the MATLAB platform and tested with three case studies. The overall energy saving percentage obtained by the proposed hybrid technique for three cases are 25, 38, and 54.5%, respectively. [ABSTRACT FROM AUTHOR]

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Aiming at the three-body contact problem of mechanical rough surface containing wet coal dust interface, the three-body contact model of rough surface containing wet coal dust interface is constructed by comprehensively considering the contact deformation of rough surface and contact characteristics of wet coal dust, and based on the crushing theory. By analysing the contact force, load-bearing particle size and adjacent contact angle thresholds of the wet coal dust layer, the force chain identification criterion is formulated. Finally, quantitative calculations of the force chain characteristics are performed to reveal the effect of different initial porosities on the three-body contact stiffness, which is verified experimentally. The results of the study show that the average contact force of the wet coal dust layer can be used as the force chain contact force threshold, the average particle size can be used as the force chain particle size threshold, and the force chain angle threshold is determined by the particle coordination number. As the initial porosity decreases, the number, length and stiffness of force chains in the wet coal dust layer increase significantly, and the stiffness reaches a maximum value of 2.007 × 108 pa/m at the moment of downward pressure to stabilisation, while the trend of force chain bending varies in the opposite direction, and its minimum bending degree decreases to 20°. The maximum relative error between the simulation and experimental results of three-body contact stiffness is 9.64%, which proves the accuracy of the force chain identification criterion and the quantitative calculation of three-body contact stiffness by force chain. [ABSTRACT FROM AUTHOR]

Open-pit mine pavement dust dries and breaks easily. As such, a composite pavement dust suppressant with good wettability, moisturizing, coagulation, and antifreezing properties in winter was investigated. Monomer screening and orthogonal experiments were conducted, using evaporation rate, permeability rate, viscosity, and freezing point as evaluation indexes. Consequently, a dust suppressant solution is a mixture of glycerol (GLY), sodium dodecylbenzene sulfonate (SDBS), polyacrylamide (PAM), compound propylene glycol (PG), and potassium acetate (PA). The characteristics of the dust suppressant and its interaction mechanism with road dust were measured and analyzed. The results showed that the optimal ratio of the antifreeze-type composite dust suppressant is 3%GLY, 0.30%SDBS, 0.07% PAM, and 50%PG + 10%PA; the contact angle is 27.62°, which can effectively wet coal dust. Moreover, it easily forms hydrogen bonds with water molecules to release free -OH, which increases the oxygen-containing functional groups in the dust. The maximum viscosity is 25.4 mPa·s, and the hydrophobic groups adsorbed on the surface of the dust can condense and agglomerate the dust to form large particles, and effectively inhibit the occurrence of dust. It freezes at − 34.2 ℃, resists a temperature of − 30 ℃ without freezing, and improves dust suppression efficiency and antifreezing effect in cold areas. [ABSTRACT FROM AUTHOR]

Purpose: Coal mining is a vital sector in Colombia, contributing significantly to the nation's economy and the development of its regions. However, despite its importance, it has led to a gradual decline in the health of mine workers and nearby residents. While the adverse health effects of open-pit coal mining on exposed individuals have been well-documented in Colombia and globally, studies investigating genetic damage in underground coal miners are lacking. Methods: The aim of our study was to evaluate chromosomal and genotoxic damage, in peripheral blood samples from a group of underground coal miners and residents of areas exposed to coal, in the town of Samacá, Boyacá-Colombia, and in a group of unexposed individuals by using banding and molecular cytogenetic techniques, as well as cytokinesis block micronucleus assays. Results: Our results suggest that occupational exposure to coal induces chromosomal and genotoxic damage in somatic cells of underground coal miners. Chromosomal and genotoxic damage is an important step in carcinogenesis and the development of many other diseases. Our findings provide valuable insights into the effects of coal dust exposure on chromosomal integrity and genetic stability. Conclusion: Our pilot study suggests that occupational exposure to coal induces chromosomal damage in underground coal miners, highlighting the importance of validating these findings with a larger sample size. Our results highlight the need to implement prevention and protection measures, as well as educational programs for underground coal miners. Characterizing and estimating exposure risks are extremely important for the safety of people exposed occupationally and environmentally to coal and its derivatives. [ABSTRACT FROM AUTHOR]

This paper considers extreme dusty conditions at workplaces in underground coal mine. These extreme conditions stem from various physical factors that affect employees' performance. The extreme effect of the dust can significantly contribute to permanent health damage or even the death of employees. In this study, we present and discuss the results of measurements of airborne dust and respiratory dust taken during wall cutting in a coal mine and propose effective measures to reduce the burden on the life and health of employees and the environment. [ABSTRACT FROM AUTHOR]

Improving the mean size of surface coke is an important subject in coke-making process. Focusing on usage of crushed inertinite, we investigated on addition of coke dry quenching (CDQ) dust in coal blend in different compositions. The effect of addition of CDQ dust on coke quality including coke mean size, changes in size fractions and coke CSR was studied. CDQ dust acts as crushed inertinite and helps in minimizing the decrease in coke strength occurred because of small cracks generated during carbonization. These cracks are generated because of different contraction ratio of vitrinite and inertinite. After taking plant trials with varied CDQ dust composition from 1% to 3% in coal blend, 1% CDQ dust usage in coal blend revealed as the optimized percentage for achieving higher mean size. [ABSTRACT FROM AUTHOR]

The suppression effect of inert powder on gas-induced suspension coal dust explosions was investigated using a semi-closed pipeline experimental platform. The shock wave overpressure propagation characteristics of gas explosions with different concentrations of mixed dust (calcium carbonate and coal dust) were measured and analyzed. The suppression mechanism of inert powder on the explosion process was also discussed. The results indicate that when the coal dust concentration is 200 g/m³, the peak overpressure of the explosion decreases gradually with increasing inert powder concentration, and the peak overpressure ratio in the pipeline shows a decreasing-increasing trend. The acceleration of the explosion pressure reduces with increasing mixed dust concentration, and when high concentration of mixed dust is involved in the explosion, the acceleration of the explosion pressure is lower than that when only coal dust is involved. The inhibitory effect of calcium carbonate on dust explosion increased linearly with its concentration when the ratio of inert dust to coal dust was 1:2. Inert powder mainly suppresses the explosive power by physical heat absorption and reducing heat exchange efficiency. The experimental results established the theoretical basis for inert dust suppressing coal dust participation in explosions, and have reference significance for formulating mine explosion suppression measures. [ABSTRACT FROM AUTHOR]

The challenges of the modern world largely concern the energy sector and determine the search for new envi- ronmentally friendly and, above all, renewable energy sources. We can consider biochar or materials obtained by pyrolysis as an alternative and green fuel. Substrates for the production of such fuels can be biomass of agricultural origin, including straw. In the present study, wheat straw, oat straw, and triticale straw were used to produce pyrolysates. This paper evaluates the modifica- tion of pyrolysis parameters by assessing selected properties of pyrolysates, focusing on the calorific value and parameters characterizing the dust explosion hazard. There was an average increase of 30% in the calorific value of all biocarbons prepared from the three types of straw in relation to the control sample. The anaerobic thermal treatment resulted in a maximum increase in the calorific value to 26.43 MJ kg -1. An increase in such parameters as dust explosive index, the maximum rate of pressure buildup and the maximum explosion pressure was found. However, there was no effect on the increase in the dust explosion risk. Noteworthy, the results indicate that it is possible to use various types of straw to produce biochar fuels by anaerobic thermal treatment without increasing the probability of dust explosion. [ABSTRACT FROM AUTHOR]

Exposure to respirable coal mine dust (RCMD) still poses health risks to miners. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) is a powerful tool for RCMD characterization because it provides particle-level data, including elemental ratios (via the EDX signals) that can enable classification by inferred mineralogy. However, if the particle loading density (PLD) is high on the analyzed substrate (filter sample), interference between neighboring particles could cause misclassification. To investigate this possibility, a two-part study was conducted. First, the effect of PLD on RCMD classification was isolated by comparing dust particles recovered from the same parent filters under both low- and high-PLD conditions, and a set of modified classification criteria were established to correct for high PLD. Second, the modified criteria were applied to RCMD particles on pairs of filters, with each pair having one filter that was analyzed directly (frequently high PLD) and another filter from which particles were recovered and redeposited prior to analysis (frequently lower PLD). It was expected that application of the modified criteria would improve the agreement between mineralogy distributions for paired filters; however, relatively little change was observed for most pairs. These results suggest that factors other than PLD, including particle agglomeration, can have a substantial effect on the particle EDX data collected during direct-on-filter analysis. [ABSTRACT FROM AUTHOR]

The ecology of mining areas has been one of the most crucial components in terrestrial ecosystems. However, the over-exploitation of mineral resources has posed a great threaten to the ecosystem in recent years, leading to frequent environmental issues, such as land degradation, vegetation loss, and water scarcity. Therefore, accurate monitoring of mining ecology is of great importance to protect the ecological environment and balance. Remote sensing technology can be expected to provide an effective means for the ecological monitoring in mining areas. In this study, Remote Sensing Ecological Index (RSEI) was improved to realize the overall spatial average on the indicator weights for the ecological monitoring of mining sites. The factor of coal dust pollution was also added into the conventional greenness, wetness, dryness and heatness. The indicator weights were then determined using Geographically Weighted Principal Component Analysis (GWPCA). The indicator was finally selected to construct Geographically Weighted-Remote Sensing Ecological Index (GW-RSEI). Taking the Datong coal field in Shanxi Province as an example, the validity and applicability of GW-RSEI were verified for monitoring mining area ecology using multi-phase remote sensing images from 2000 to 2020. The results showed that the indicator weights of GW-RSEI were varied continuously over the space, indicating the spatial heterogeneity within different local surface areas. GW-RSEI shared the average correlation coefficients with universal normalized vegetation index (UNVI), normalized difference moisture index (NDMI), soil index (SI), temperature vegetation dryness index (TVDI) and index-based coal dust index (ICDI) of 0.76, 0.78, -0.77, -0.82 and -0.41, respectively, (P<0.05). Furthermore, the GW-RSEI was integrated each indicator to fully reflected the ecological environment of mining areas. The overall monitoring that obtained by GW-RSEI was similar to that by RSEI over the past two decades. However, the GW-RSEI was focused on the real ecological impacts at the surface, indicating the more reliable at local scales. Whether in areas with single or complex land use types, GW-RSEI exhibited the higher correlations with soil moisture (SM), net primary productivity (NPP) and particulate matter 2.5 (PM2.5) than RSEI. The GW-RSEI monitoring was more consistent with the actual surface, in order to effectively reflect the ecological environment of the mining areas. Therefore, the GW-RSEI was successfully used to monitor the severe pollution of coal dust in local coal mining activity areas. The grade of GW-RSEI was lower than that of RSEI in the areas with the severe pollution of coal dust. The trend was the gradually increasing from the area with the high level of coal dust pollution as the center to the surrounding areas, indicating the spatial pollution in mining areas. The GW-RSEI values were higher than RSEI ones in urban areas of the county with the medium to high vegetation cover, and in rural areas where the land type was mainly arable land and grassland. There were significantly more medium to low GW-RSEI value in the mining area and surroundings, compared with the RSEI. Furthermore, the gradual trend was highlighted the spatial continuity in ecological environment quality. GW-RSEI averages were 0.51, 0.48, 0.46, 0.59, and 0.56, indicating that the overall ecological environment experienced a process of first deterioration and then improvement. The trend in the southeastern region of Datong Coal field was consistent with the overall trend, while the northwestern region showed a trend of first improvement and then deterioration. The GW-RSEI can provide the more effective way to accurately monitor the ecology of the mining area. [ABSTRACT FROM AUTHOR]

Coal dust is one of the environmental factors that seriously affect the health of workers as well as the mining equipment in underground coal mines. At present, coal dust is commonly generated during drilling, blasting, excavation, and transportation processes in mining operations. During mining blasting processes, coal dust is generated with varying particle sizes and high concentration levels. High concentrations of dust will affect mining operations and increase the ventilation time required for mining faces. In addition, coal dust exists in suspended form in the roadway and is harmful to human health, especially fine dust particles that have a negative impact on work efficiency. To improve ventilation efficiency and eliminate coal dust, this article presents a CFD-DPM numerical modeling method that integrates a DEM collision model based on the finite element method to analyze the motion characteristics of airflow and dust particles in the mine tunnel, while considering collisions between particles and between particles and walls. The article analyzes the distribution of wind speed, the dispersion of dust in the space around the roadway, and dust concentrations at distances of 1 m, 3 m, and 6 m from the working personnel and at a position 1.5 m above the roadway floor, corresponding to the breathing zone of the workers, with varying parameters such as velocity and duct position. The results indicate that with a wind velocity of V = 18 m/s and an air duct height h = 3.0 m, the best dust reduction results are achieved, and they provide theoretical guidance for selecting and optimizing ventilation parameters in dust control. [ABSTRACT FROM AUTHOR]

Purpose: In coal mining regions, soil organic carbon content is elevated by the deposition of coal dust through natural settling and transportation. However, the contribution of organic carbon content from coal dust of varying coalification degrees is inconsistent. Its active involvement in soil carbon transformation processes and its influence on soil bacterial communities remain to be elucidated. Methods: This study conducted a 120-day indoor constant-temperature soil incubation experiment, with sampling carried out at 5, 15, 30, 50, 80, and 120 days of incubation. The research aimed to investigate the impact mechanisms of three coalification degrees of coal dust, lignite, bituminous coal, and anthracite, along with a corresponding control group, on soil carbon dioxide (CO2-C) accumulation mineralization, soil active organic carbon, and soil bacterial community structure. Results: Lignite exhibited the highest promotion of soil CO2-C mineralization, showing a 9.74% increase compared to the control (CK). The impact of the three types of coal dust on soil readily oxidizable organic carbon (ROC) and microbial biomass carbon (MBC) content decreased to varying degrees with increasing incubation time. Furthermore, coal dust was found to enhance the prevalence of dominant bacterial taxa in the soil, with an increase in groups such as Proteobacteria, Actinobacteria, and Acidobacteria, and the extent of the increase was correlated with the coalification degree. Conclusion: Coal dust with lower coalification degrees has a stronger impact on the soil compared to higher coalification degrees, and these effects tend to manifest in the short term. Therefore, further exploration of this aspect should focus on long-term effects. [ABSTRACT FROM AUTHOR]

To control the diffusion of high concentrations of coal dust during tunnel boring and minimize the threat to the life and health of coal miners, theoretical analysis, numerical simulations, and field measurements were combined in this study. First, computational fluid dynamic simulation software was used to simulate the generation of dust particles and their transport pattern in the tunnel. Subsequently, an innovative orthogonal test was performed to study the effect of four ventilation parameters [the pressure airflow rate (Q), distance between the air duct center and heading face (LA), distance between the air duct center and tunnel floor (LB), and distance between the air duct center and nearest coal wall (LC)] on dust diffusion. According to the orthogonal test results, the optimal ventilation parameters for effective dust control are as follows: Q = 1400 m3/min, LA = 7 m, LB = 2.8 m, and LC = 1 m. The optimized set of ventilation parameters was applied to the Wangpo 3206 working face. The results show that dust diffusion in the tunnel was effectively controlled and that the air quality was sufficiently improved. [ABSTRACT FROM AUTHOR]

To effectively control the dust generated by coal mining operations, a new type of cyclonic pneumatic mist curtain dust control device was developed. Using CFD software, numerical simulations were conducted on the internal airflow velocity field, the exit velocity of the cyclonic pneumatic mist curtain, and the mist droplet particle field of the curtain. Experiments were carried out to measure the spray coverage, droplet size, and the dust control performance of the model device. The results indicate that when the water pump supply pressure is 8 MPa, the fan supply wind speed is 12 m/s, and the nozzle installation angle is 75 degrees, the cyclonic pneumatic mist curtain dust control device model operates under optimal conditions. The effective coverage of the cyclonic mist curtain is 380 × 3300 mm, fully suppressing dust generation on one side of the curtain. An optimal dust removal distance of about 90 cm was determined. After installing the cyclonic pneumatic mist curtain dust control device, the average dust reduction efficiency for respirable dust reached 91.07%, and the overall dust reduction efficiency achieved 93.34%. [ABSTRACT FROM AUTHOR]

The poor plasticity of coal results in a large amount of dust during the mining process, thereby posing a significant impact on mine safety and the health of workers. In order to address this issue, a method has been proposed to suppress dust by enhancing the plasticity of coal through injecting a reactive material, which forms a colloid within the coal. The results implicated that the self‐active colloidal dust suppressant, composed of sodium alginate, gluconolactone, calcium disodium EDTA, and sodium dodecyl sulfate, effectively improved the moisture content of coal seams and decreased the brittleness of coal. Scanning electron microscopy and specific surface area test revealed that the dust suppressant not only tightly adheres to the surface of the coal after the reaction, but also penetrates the coal pores and forms a colloid on both the inner and outer surfaces of the coal. The material is rich in carboxyl and hydroxyl groups, which forms hydrogen bonds with the carboxyl and hydroxyl groups present in coal. This interaction enhances the toughness of coal. Simultaneously, it has the ability to adsorb water and function as a moisturizer. The combined synergistic effect of these mechanisms fundamentally reduces dust production during the coal mining process. [ABSTRACT FROM AUTHOR]

To enhance the real-time monitoring and early-warning capabilities for dust disasters in underground coal mine, this paper presents a novel WGAN-CNN-based prediction approach to predict the dust concentration at underground coal mine working faces. Dust concentration, wind speed, temperature, and methane concentration were collected as the original data due to their nonlinear relationship. The consistency between the generated and original data distributions was verified through PCA dimensionality reduction analysis. The predictive performance of this approach was assessed using five metrics (R2, EVS, MSE, RMSE, and MAE) and compared with three other algorithms (Random Forest Regressor, MLP Regressor, and LinearSVR). The findings indicate that a majority of the generated data falls within the distribution range of the real dataset, exhibiting reduced levels of volatility and dispersion. The R2 values of prediction results are all above 98%, and the MSE values are between 0.0007 and 0.0106. The proposed approach exhibits superior predictive accuracy and robust model generalization capabilities compared to alternative algorithms, thereby enhancing the real-time monitoring and early-warning level of dust disasters in underground coal mine. This will facilitate the realization of advanced prevention and control measures for dust disasters, showcasing a wide range of potential applications. [ABSTRACT FROM AUTHOR]

High-power ore furnaces mainly use single-phase transformers supplied by phase-to-phase voltage with the secondary winding made in the form of four to eight isolated splits and a high-voltage busbar assembly made of the same number of pairs of tube buses. Due to these design features, turn-to-turn faults are the main faults in the primary winding of the transformer, and flexible coupling breaks and arc faults in splitting circuits prevail in the high-voltage system. This is why current and gas protections are currently used to protect transformers against short circuits. However, current protections are insensitive to turn faults, and the gas protection response time can be long since it strongly depends on the oil temperature. High-current systems are protected from arc faults only by insulating tube buses. However, this insulation is gradually destroyed under the impact of abrasive dust in the air, and the presence of coal dust in the air creates conditions for arc faults. There is no protection against breaks in the circuits of pairs of tube buses. The extent of damage in a transformer and its high-current system due to the faults can be significantly reduced by using new protection devices based on the measurements of the longitudinal and transverse asymmetry of the stray magnetic fields of the protected transformer. To implement these protections, this article suggests a method for protecting a transformer and a high-current system using magnetic current transformers (MCTs). The number and points for MCT winding coils are determined through the analysis of their EMF values versus their positions relative to the windings of the transformer operating under different modes. The results serve as the basis for the protection circuit design; the protection response threshold is calculated, the protection operation is described, and the results of the experiment are given. [ABSTRACT FROM AUTHOR]

Role of dust in Salmonella transmission on chicken farms is not well characterised. Salmonella Typhimurium (ST) infection of commercial layer chickens was investigated using a novel sprinkling method of chicken dust spiked with ST and the uptake compared to a conventional oral infection. While both inoculation methods resulted in colonisation of the intestines, the Salmonella load in liver samples was significantly higher at 7 dpi after exposing chicks to sprinkled dust compared to the oral infection group. Infection of chickens using the sprinkling method at a range of doses showed a threshold for colonisation of the gut and organs as low as 1000 CFU/g of dust. Caecal content microbiota analysis post‐challenge showed that the profiles of chickens infected by the sprinkling and oral routes were not significantly different; however, both challenges induced differences when compared to the uninfected negative controls. Overall, the study showed that dust sprinkling was an effective way to experimentally colonise chickens with Salmonella and alter the gut microbiota than oral gavage at levels as low as 1000 CFU/g dust. This infection model mimics the field scenario of Salmonella infection in poultry sheds. The model can be used for future challenge studies for effective Salmonella control. [ABSTRACT FROM AUTHOR]

The air-supported membrane coal shed is widely used in bulk cargo terminals. It not only effectively protects goods from adverse weather conditions but also helps reduce coal dust and harmful gas emissions, promoting the green and sustainable development of ports. However, in practical engineering, the design parameters of the coal shed are often based on experience, making it difficult to accurately assess the quality of the structural design. The flexibility of the membrane material also makes the structure susceptible to deformation or tearing. This paper mainly focuses on modeling and solving the optimization design issues of air-supported membrane coal shed structures. According to the evaluation criteria for the form of air-supported membrane coal sheds, a multi-objective structural optimization model is established to minimize the maximum stress on the membrane surface, ensure uniform stress distribution, maximize structural stiffness, and minimize costs. The study utilizes a combined optimization approach using ANSYS 19.0 and MATLAB 2016a, incorporating an improved NSGA-II algorithm program developed in MATLAB into ANSYS for structural form analysis and load calculation. The research results indicate that the optimal solution reduces the maximum stress on the loaded membrane surface by 5.36%, shortens the maximum displacement by 30.3%, and saves on economic costs by 9.85%. Compared to traditional empirical design methods, the joint use of MATLAB and ANSYS for optimization design can provide more superior solutions, helping ports to achieve environmental protection and economic efficiency goals. [ABSTRACT FROM AUTHOR]

This paper presents a concept of a routing algorithm for a network of sensors monitoring the condition of machinery and equipment operating in areas at risk of methane and/or coal dust explosion. It was assumed that the proposed algorithm would find application in sensor networks monitoring, among other things, oil pressure in powered roof supports and the position of powered roof support elements. The results of a literature analysis were presented, which included the simulation of sensor network routing algorithms, including, among others, reactive algorithms, proactive algorithms and algorithms based on so-called swarm intelligence (SI). As a result of the analyses, several algorithms were selected and implemented in a prototype sensor network. The characteristics of each of these algorithms are described. The article includes a description of the commissioning work of the network, which consisted of between 3 and 30 nodes. An analysis of the collected measurement data obtained for each criterion of the performance evaluation of the routing algorithms is presented. [ABSTRACT FROM AUTHOR]

Coal dust is a major safety hazard in the process of coal mining and is of great importance to ensure production safety and maintain the health of operators. In order to understand the microscopic mechanism during coal seam water injection and reveal the mechanism of surfactants in improving the wettability of coal dust, coking coal was selected as the research object. Three surfactants, SDBS, AEO-9, and CAB-35, were chosen for molecular dynamics simulation research on the wetting and adsorption properties of water/coal/surfactants. The results show that surfactant molecules can cover the hydrophobic groups on the surface of coking coal, forming a hydrophilic adsorption layer, changing the coal surface from hydrophobic to hydrophilic, and enhancing the wettability. After adding surfactants, the thickness of the adsorption layer in the z-axis direction increases, expanding the contact area between coking coal and water molecules, thereby improving the wettability. When surfactants tightly cover the surface of coking coal, their binding strength increases, forming a more stable hydrophilic layer and further improving the wettability. At the same time, surfactants promote the diffusion of water molecules and enhance the interaction between hydrophobic alkyl chains and water molecules, further enhancing the wetting effect. [ABSTRACT FROM AUTHOR]

Relevance. Russian coal exports have been steadily increasing in recent years, and Far Eastern ports, originally not adapted to dusty cargoes, have switched to coal operations. Unoptimized coal handling leads to increased content of coal-containing particles in the air and to various environmental problems. Aim. To analyze the concentration of particulate matter in the air and the chemical composition of particles on the surface of conifer needles in the Posyet settlement (Primorsky Krai, Russia), where a large coal terminal operates. Materials and methods. The chemical composition was studied on the surface of conifer needles by X-ray fluorescence and in washout of conifer needle samples using Raman spectroscopy and energy dispersive analysis. Concentrations of particles with the diameter of 2.5 and 10 μm (PM2.5 and PM10, respectively) were measured using automatic monitoring stations. Results and conclusions. Chemical composition was dominated by mineral particles (calcite, silicates, etc.). However, the presence of coal particles (up to 8.3%) and metal particles was also observed. Mean concentrations of PM2.5 and PM10 were within the Russian and international health standards, but close to their upper limits. Concentrations of both measured particle fractions were highest during the winter months (as well as in March, which is traditionally a cold month in the Far East), followed by a gradual decrease. The study obtained new data on the annual variations of concentrations of PM2.5 and PM10, as well as on the basic composition of particles from the surface of woody vegetation (needles) as an indicator of the state of air pollution in this settlement.

Abstract To discuss the inhibitory effect of micrometer scale coal dust explosion pressure, three types of explosion suppressants are selected for mixed explosion suppression. The results indicate that the coal dust explosion process includes three stages: accelerated and decelerated energy release, as well as energy dissipation. When using explosive suppressants, K2CO3 has the greatest inhibitory effect on coal dust explosion, followed by KCl, and CaCO3 has the smallest effect. The K2O, K2O2, and KOH generated by the thermal decomposition of K2CO3 can also block the heat transfer of coal dust, playing a good role in suppressing explosions. The explosion suppression effect of mixing CaCO3 and K2CO3 is better than that of mixing CaCO3 and KCl, and is worse than the explosion suppression effect of using K2CO3 alone. The synergistic effect of KCl and K2CO3 mixed explosion suppression makes the suppression effect better than using K2CO3 alone. This is because KCl generates K2O during pyrolysis, promoting the dynamic equilibrium of K2CO3 explosion suppression process. This makes mixed explosion suppression more worthy of attention and adoption when considering purchase costs.